Visual MODFLOW Tutorial
Contents
1. Evenly spaced gridlines from Click inside the adjacent text box and enter the following values from 500 lt gt to 1600 lt gt at intervals of 25 cS OK to accept these values iS Close to exit the Columns dialog box Now we ll refine the grid in the y direction from the refuelling area to the supply wells m Edit Grid am Edit Rows Move the mouse to anywhere in the model grid and click on the RIGHT MOUSE BUTTON A dialog box will prompt you for grid information Evenly spaced gridlines from Click inside the adjacent text box and enter the following values Section 2 Refining the Model Grid 7 from 400 lt gt to 1900 lt at intervals of 25 iS OK to accept these values va Close to exit the Rows dialog box The refined grid should appear as shown in the following figure Visual MODFLOW C VMODNT Tutorial Airport LTEM File Grid Wells Properties Boundaries Particles ZBud Tools Help View Row Y 1762 0 zZ 150 Row lI 8 Column ful 25 Layer K 1 Grid edit module The following steps will show you how to view the model in cross section and add ne layers to the model To view the model in cross section iw View Column from the left hand menu Move the mouse cursor anywhere in the grid As you move the cursor across the screen a bar highlights the column corresponding to the cursor location To select a column to view click the left m2. Grid edit module This is the Visual MODFLOW Input module The top menu bar of the Input module is divided into the primary building blocks for any groundwater flow and contaminant transport model Grid Wells Properties Boundaries and Particles Each of these menu items provides access to an associated Input screen The left hand menu bar provides a list of graphical tools associated with the selected Input screen The Navigator Cube on the lower left hand side of the screen shows the location of the current row layer and column in the model and theX Y Z and I J K location of the mouse pointer Section 2 Refining the Model Grid The Grid screen provides a complete assortment of graphical tools for delineating inactive zones refining the model grid importing layer surface elevations optimizing smoothing the grid spacing and contouring the layer surface elevations This section describes the steps necessary to refine the model grid in the areas of interest such as around the supply wells and around the refuelling area The reason for refining the grid is to get more detailed simulation results in areas of interest or in zones where you anticipate steep hydraulic gradients If drawdown is occurring around the well the water table will have a smoother surface with finer grid spacing You are currently located in the input module where the building blocks for a model appear in the menu bar Visual MODFLOW loads
3. pz Edit Well from the left toolbar Select the new east well by clicking on the well symbol An Edit Well dialog box will appear Click and highlight the text in the text box labelled Well Name type Supply Well 2 Click in the text box labelled Rate m3 d type 550 v OK to accept these well parameters is F6 Zoom Out Section 4 Assigning Model Properties This section will guide you through the steps necessary to design a model with layers of highly contrasting hydraulic conductivities 1s Properties on the top menu bar is Conductivity Zs Yes to save your data 14 Visual MODFLOW Tutorial If you are creating a new model a Default Property Values dialog box will appear at this point prompting you to enter initial values for hydraulic conductivity specific storage specific yield and porosity These values will then be assigned to each cell in the model Hydraulic conductivity distributions can be graphically assigned to any region of the model in layer view or in cross section using the Assign Single Assign Polygon or Assign Window tools Enter the following values using the format indicated Hydraulic Conductivity in x Kx m s 2e 4 Hydraulic Conductivity in y Ky m s 2e 4 automatic Hydraulic Conductivity in z Kz m s 2e 4 Specific Storage Ss 1 m le 4 Specific Yield Sy 0 2 gt Effective Porosity Eff Por 0 15 Total Porosity Tot Por 0 15 iS OK to accept thes
4. S View Layer from the left toolbar Then highlight the top layer of the model and click with the left mouse button This should create a plan view display of the airport site 12 Visual MODFLOW Tutorial Section 3 Adding Wells The purpose of this section will be to guide you through the steps necessary to assign pumping wells to the model S Wells from the top menu bar Lg Pumping Wells from the drop down menu You will be asked to save your data us Yes to continue Once your model has been saved you will be transferred to the Well Input screen Notice that the left menu options are new well specific options To start zoom in on the area surrounding the supply wells lower right hand section of the model domain uam F5 Zoom In Move the cursor to the upper left of the supply wells and click on the left mouse button Then stretch a box around the supply wells and click again to close the zoom window To add a pumping well to your model S Add Well Move the cursor to the west well and click on it A New Well dialog box will appear prompting you for specific well information EN New Well OF x D ES H Well Name Supply Well 1 gs 1252 m v 536 1089 m Z 0 55 m Screened Intervals pK Screen Bottom m Top m 18 32745 gt 10 3 E 14 45237 10 57729 Pumping Schedule gt P DA CO 9 387329 Start days End days Rate m d 8 197369 p 0 00 7300 400 t 4 221
5. 1825 days by clicking on the number 1825 this row will become highlighted OK A plot of concentration contours will appear which plots the concentrations for the first output time of 1825 days Since it is often easier to represent concentration contours with logarithmic scale and in color you can customize the contour display as follows iw Options Contours Color Shading IV Automatic reset min max and interval values Minimum 500 E Automatic contour levels eco PRN e w Custom contour levels Interval 500 mg L m Contour Label v Visible fi Decimals Color BI Marcon width 1 4 Contouring resolution Speed Deactivate O Automatic contour levels Activate M Custom contour levels Enter the following custom contour levels in the text boxes provided 0 1 100 1 500 1 1000 1 2000 4000 Although this is not a strictly logarithmic scale it does provide a much better representation of the concentration contours iS Highest Slowest to change it to High Slow Next S Colour Shading tab Activate M Use Color shading Section 15 Concentration Contours 47 48 In the Ranges of Colour section for the minimum value type 0 Activate M Lower Cut of levels type 0 5 this partially eliminates numerical dispersion from the display gi Results JP 4 Lx Contours Color Shading M Use Color Shading NE Minimum 500 ma L Basic point Maxim
6. The following dialog box will appear Section 2 Refining the Model Grid 9 10 Import Surface Import Data World Coordinates From ASCII s y z From Surfer ard Import Filename C vmodnt T utorialXAirpt gs asc Surface Op Import ground surface C Import bottom elevation of Minimum Layer Thickness i Use 5 Nearest Sample Points is Choose Filename An Import Surface dialog box will appear listing the available ASC TXT and XYZ files The file you will import for the ground surface elevations is airpt gs asc To select the ground surface topography file SiS airpt_gs asc To accept the remaining default settings ad OK This will import a variable surface generally sloping from 20 meters at the northern boundary to 17 meters at the southern boundary Visual MODFLOW reads the x y z data from the file and uses an inverse distance squared interpolation routine to assign block center elevations for the top of each cell in layer 1 using the five nearest sample data points Now you will import the surface elevations for the bottom of layer 1 1S Import Elevation is Choose Filename Isis airpt bl asc to select the elevation data for the bottom of layer 1 is Import bottom elevation of Layer 1 the value in box by default is 1 Minimum Layer Thickness 0 75 iS OK to select the remaining default parameter values After a few seconds the bottom of layer 1 will
7. X 2294 6 B ES Row l 600 300 1200 Column J FY Foren Eee Fr F8 vert Layer K S out A Pan Ki esq Output Time 1 00000 day Stress period 1 Time step 1 F3 To make the velocity vectors independent of magnitude 42 Visual MODFLOW Tutorial Zs Direction from the left toolbar All of the arrows will then be plotted as the same size and simply act as flow direction arrows ws Options from the left menu Change the number of vectors displayed by typing Vectors 40 This specifies the number of velocity vectors along a single row va M Autoscale var Variable Scale 1S OK to accept the velocity vector settings To see the site in cross section select the View Column button from the left hand menu and then move the mouse into the model domain and click once to select any column A display similar to the following figure will appear showing both the equipotentials and velocity vectors in cross section To show the discretization of the hydraulic conductivity layers select the F9 Overlay button from the bottom menu bar An Overlay Control dialog box will appear with an alphabetical listing of all the available overlays that you may turn on or off Locating the Prop Conductivity double click on it to select it This should add an asterisk beside the Prop Conductivit indicating that it has been activated ps OK to show the cross section with the hydraulic conductivity layers Notic
8. appear with a variable layer surface Next you will import the surface elevations for the bottom of layer 2 1S Import Elevation Visual MODFLOW Tutorial ua Choose Filename to select the input data file to import xc airpt b2 asc to select the elevation data for the bottom of layer 2 m Import bottom elevation of Layer Layer 2 Minimum Layer Thickness 0 75 mns OK to select the remaining default parameter values The bottom of layer 2 will then appear with a variable layer surface Next you will import the surface elevations for the bottom of layer 3 i Import Elevation from the left toolbar iS Choose Filename acd airpt b3 asc to select the elevation data for the bottom of layer 3 a Import bottom elevation of Layer Layer 3 Minimum Layer Thickness 0 75 re OK to select the remaining default parameter values The bottom of layer 3 will then appear with a variable layer surface To obtain a finer vertical discretization of the model grid you will subdivide each of the layers From the left toolbar iS Edit Grid 1S Edit Layers Move the mouse into the model cross section A deforming horizontal line will follow the mouse elevation within the model cross section To sub divide a layer move the line to the approximate vertical mid point of layer 1 and press the left mouse button A layer division will be added in this location To sub divide the middle confining layer move the mouse such that the hor
9. be similar to the following plot The following figure does not however show color shading Visual MODFLOW C wmodnt T utorial Airport vmf File Contours Velocities Pathlines Budget Annotate Tools Help Column J F3 Quer Layer K 1 Fay Output Time 1 00000 day Stress period 1 Time step 1 Other contouring options that are not activated by the menu buttons can be activated by pressing the RIGHT MOUSE BUTTON inside the model domain This will bring up a shortcut menu with options to add delete and move contours and labels Select the Add Contour option and then move the mouse Add contour s anywhere in the model domain and click the LEFTMOUSE Delete contour s BUTTON once A contour line will be added in the location Delete all custom where you click the mouse Toadd another contour line simply Add label s click the LEFT MOUSE BUTTON again To finish adding contour lines click the RIGHT MOUSE BUTTON once To retrieve the shortcut menu simply press the RIGHT MOUSE BUTTON again This time select the Move Label option and move the mouse to the location of a contour label you wish to move Press and hold the mouse on the label and then drag the label to the desired location along the contour line and release the mouse button to set the new label location When you are finished moving contour labels press the RIGHT MOUSE BUTTON once more Delete label s Move label s Next take a look at the site
10. every 1000 day C Custom v Use time markers C Segments highlight Show all pathlines Start in current layer Reset DK Cancel To see how far the pathlines would go in 10 000 days uae Time Related and enter a value of 10 000 in the box Notice that M Use time marks option is active The time marker interval is indicated in the box labelled 9 Regular every 1000 days um OK to view the time related pathlines up to a time of 10 000 days Now view the pathlines in cross section us View Column Move the cursor across the screen until the highlight bar is in the vicinity of the zone of discontinuous aquitard and click on it Now we will revert back to the plan view display 1S View Layer Move the cursor across the screen until the highlight bar is on the first layer and click on it To remove the pathlines from the display select the F9 Overlay from the left toolbar and scroll down the overlays until you see Misc Particles and Results Path Lines Deactivate both of these overlays by double clicking on them to remove the asterisk d OK Section 15 Concentration Contours In this section you will learn how to display your contaminant transport results Contours from the top menu bar va Concentration To view the concentration contours for an output time Visual MODFLOW Tutorial D Time from the left toolbar A dialog box will appear Select the time of
11. me Line Beginning on the south west sid eof the grid and using the sitemap as a guide digitize the river by clicking along its path with the left mouse button When you have reached the south east boundary click the RIGHT MOUSE BUTTON A dialog box will prompt you for information about the river Section 5 Assigning Model Boundary Conditions 23 24 coset A M Assign to appropriate layer Import Start Stop River Stage River Bottom Conductance Time day Time day Elevation m Elevation m m day o Sun End Pt OK Cancel Help Enter the following Code 4 Ensure that the Assign to appropriate layer box appears as M Stop time Stop time day 7300 Start Pt River Stage Elevation m 16 0 lt Start Pt River Bottom Elevation m 15 5 lt Start Pt Conductance 2 day 1000 lt gt End Pt River Stage Elevation m 15 5 lt lt End Pt River Bottom Elevation m 15 0 End Pt Conductance m day 1000 1S OK to accept these values After the river has been defined a blue line will appear delineating the grid cells that have been assigned a river boundary condition as shown in the following figure Visual MODFLOW Tutorial Visual MODFLOW C wmodnt T utorial Airport vmf File Grid Wells Properties Boundaries Particles ZBud Tools View Layer Help AS E PA TA ZB Row l il Column J 1 Layer K 1 River edit module Module II Assig
12. the Grid input screen when you first enter the input module The top six toolbar buttons on the left hand side of the screen View Column View Row View Layer Goto Previous and Next appear on Visual MODFLOW Tutorial every screen and allow you to change the model display from plan view to cross section at any time The remaining toolbar buttons describe the various functions that can be performed to modify the model grid To refine the grid in the x direction iS Edit Grid D Edit Columns A dialog box will appear on the left hand side of the screen showing the options you have for editing the grid columns The Grid Edit options allow you to Add Delete or Move gridlines automatically refine or coarsen the grid import gridlines from an ASCII text file or export the gridline coordinates to an ASCII text file By default the Add Grid Edit option is selected Move the mouse anywhere in the grid Notice that a highlighted vertical line follows the location of the mouse throughout the model grid This line may be used to add a column at any location within the model domain In this exercise you will add vertical gridlines at specified intervals by clicking on the RIGHT MOUSE BUTTON to bring up the Add Vertical Line dialog box as shown below Add Vertical Line Add single grid line at 1138 810198 m Evenly spaced grid lines from 500 000000 m to 1600 000000 m at intervals of p 1 m OK Cancel Help
13. the model domain S F6 Zoom Out Section 7 Assigning Model Transport Parameters 26 The following section outlines the steps necessary to complete a simplified transport model If you purchased the MT3D96 or MT3D99 packages the setup for this portion of the model will be the same The proprietary packages offer a more robust modeling environment which you can use to create your own models For the purposes of this tutorial the focus will be on the basic setup using the public domain MT3DMS engine For more information on the capabilities of the advanced engines and or detailed information on all of the transport engines see the Visual MODFLOW User s Manual S F10 Main Menu from the bottom toolbar You will be asked to save your data is Yes 1s Setup i Numerical Engines to view the Select Transport Variant dialog box Visual MODFLOW supports all of the latest codes for contaminant transport including MT3DMS MT3D99 and RT3D In addition Visual MODFLOW also continues to support older version of MT3D including MT3D96 and MT3D v 1 5 by the U S Dept of Defence In order to accommodate all of the available options for the newest multi species codes Visual MODFLOW requires you to setup the initial conditions for the contaminant transport scenario e g number of species names of species initial concentrations species Visual MODFLOW Tutorial parameters etc Each scenario is referred to as a Transport Variant and yo
14. the zoom window Now assign a higher recharge at the Refuelling Area ws Assign Section 5 Assigning Model Boundary Conditions 19 1S Window Move the cursor to a corner of the refuelling area Click the left mouse button drag a window across the refuelling area and click the left mouse button again The Assign Recharge dialog box will appear i New The coloured spin box will turn blue and the property text box will change to a value of 2 to indicate a second recharge zone with unique values Stop Time day 7300 lt gt Recharge mm y 250 Property ca New Multiply values by Copy schedule from Start Stop Recharge Time day Time day mm yr p pee pe vam OK to accept these values i F6 Zoom Out to return to the full screen view of the model domain The next step is to assign constant head boundary conditions to the confined and unconfined aquifers at the north and south boundaries Press the drop down arrow beside Recharge in the left hand menu Scroll up and click on Const Head va Yes to save your Recharge data The first constant head boundary condition to assign will be for the upper unconfined aquifer along the northern boundary of the model domain us Assign iS Line Move the mouse to the north west corner of the grid With the left mouse button click on the centre of the cell Then with the RIGHT MOUSE BUTTON click on the centre of the cell in the north east c
15. 901 E 0 2464338 ed as Active E Radius Elevation C Depth To o DK Cancel Click in the text box labelled Well Name type Supply Well 1 Section 3 Adding Wells 13 To add a well screen interval click once in the column labelled Screen Bottom and enter the following values Screen Bottom m 0 3 lt Screen Top m 5 0 Notice the well screen interval appears in the well bore on the right hand side of the window Alternatively you can graphically assign the well screen by clicking the RIGHT MOUSE BUTTON on the well bore and choosing Add Well Screen Then click and drag the mouse where you want to add the well screen To enter the well pumping schedule click the left mouse button once inside the text box under the column labelled End days and enter the following information End days 7300 lt gt Rate m d 400 i OK to accept this well information If you have failed to enter any required data Visual MODFLOW will prompt you to complete the table at this time The next step is to assign the well parameters for the second pumping well by using a shortcut This will allow you to copy the characteristics from one well to another location rs Copy Well from the left toolbar Move the cursor on top of the west well and click on it Then move the cursor to the location of the east well location and click again to copy the well Next you will edit the well information from the copied well
16. LOW Tutorial The bold faced type indicates menu or window items to click on or values to type in denotes a button to click on either in a window or in the side or bottom menu bars Getting Started On your Windows 95 98 NT desktop you will see an icon for Visual MODFLOW Sos ER Visual MODFLOW to start the program To skip to Module 2 Assigning Particles and Contaminant Transport Parameters go to page 25 Toskip to Module 3 Running Visual MODFLOW go to page 33 To skip to Module 4 Output Visualization go to page 38 To create a new model begin with the first Module Creating and Defining a Flow Model Module I Creating and Defining a Flow Model Section 1 Generating a New Model The first module will take you through the steps necessary to generate a new model data set using the Visual MODFLOW modeling environment us File from the top menu bar ms New A Create New Model dialog box will appear sis on the Tutorial folder Create new model Save in a Tutorial fes e zu EE 2 Airport2 vmf a Airport3 vmf a Airportd vmf a Valley vmf File name Airport Save as type visual Modflow project vmf Cancel Create a new data set by typing type Airport in the File name input box Section 1 Generating a New Model 3 iS Save Visual MODFLOW automatically adds a VMF extension onto the end of the filename The model domain and unit selection dialog box will appear In this d
17. MODFLOW determines an initial guess that remains constant for all the layers However a better guess will often significantly decrease the number of iterations required for convergence to occur For your future models you can use this feature to alter the initial head estimate since this is a simple problem the initial head estimate will be sufficient OK Section 5 Assigning Model Boundary Conditions The following section of the tutorial describes some of the steps required to assign the various model boundary conditions To assign the recharge you must be viewing the top layer of the model domain Check the cube navigator in the lower left hand side of the screen to see which layer you are in If you are not in layer 1 then use the Next Previous or Goto buttons in the left hand menu to advance to layer 1 The first boundary condition to assign is the recharge flux to the aquifer 1s Boundaries Zs Recharge If you are creating a new model a Default Recharge dialog box will appear at this point prompting you to enter initial values for recharge Visual MODFLOW automatically assigns this recharge value to the entire top layer of the model In the box enter Stop Time day 7300 lt gt Recharge mm yr 100 n OK to accept these values pap F5 Zoom In Move the cursor to the upper left of the refuelling area and click on the left mouse button Then stretch a box around the refuelling area and click again to close
18. OUSE BUTTON to close the polygon The area will become shaded The Assign Recharge Concentration dialog box will appear prompting you to enter the following Code 1 Stop Time day 7300 lt gt JP 4 mg L 5000 1S OK to accept these recharge concentration values Visual MODFLOW Tutorial Zs F6 Zoom Out to return to the full screen view of the model domain The final MT3D input parameter required is the dispersion information pz Properties from the top menu bar a Dispersion The Visual MODFLOW program automatically assigns a set of default values for each of the dispersivity variables The following table summarizes these values Longitudinal Dispersivity 10 Horizontal to Longitudinal Ratio 0 1 Vertical to Longitudinal Ratio 0 01 Molecular Diffusion Coefficient 0 0 It is possible to assign alternate values for the longitudinal dispersivity by using the Assign or Edit command buttons from the left toolbar rz Edit p Property c Ok to accept the default value In order to alter the horizontal or vertical ratios and or the molecular diffusion values you can use the Layer Options command from the left toolbar m Layer Options ne OK to accept the default values Finally you will add the three observation wells to the model to monitor the concentration at discrete locations throughout the model domain LS Wells from the top menu bar rz Conc Observation Wells
19. Visual MODFLOW Tutorial A quick and easy to use tutorial that will guide you through some of the basic concepts associated with the Visual MODFLOW software package Visual MODFLOW Avmodflow samples xsect vmf File Contours Velocities Pathlines Zbud Annotate Help eae EDS NN NN NAA Edit Well ol x b di moy Column JE 11 2 E Fs F6 F F in ot s OA x WellName owl x 760 m y 1667 m Z 0 80 m ime step a X Layer K 11 Species Name JP 4 Observation Points gt yX CD Observation Point Elevation m 19 299 B ANNA S Nw gt 176 ka 15 42 P 11 54 A 8 8878 m 8 1857 bservations y UE I E Time days 4 0796 Visual MODFLO NvmodntSD rumcoXD rumcow wmf 0 036379 View Coli 5 EH cum Display as View Row i v Elevation C Depth To Z Row l Column Jl Layer K Output Time 1 00000 day Stress period 1 Time step 1 1999 Waterloo Hydrogeologic Inc Visual MODFLOW Tutorial Table of Contents Description of the Example Model How to Use this Tutorial Terms and Notations Getting Started Module I Creating and Defining a Flow Model Section 1 Generating a New Model Section 2 Refining the Model Grid Section 3 Adding Wells Section 4 Assigning Model Properties Section 5 Assigning Model Bo
20. You will be prompted to save your data Zs Yes Add Obs Move the mouse anywhere in the model domain and click the left mouse button A New Well dialog box will prompt you for the following information Section 9 Designating the Contaminant Source 31 E New Well olx D WelName O W1 z x 760 m yf 667 m Z 17 55 m Species Name JP 4 m Observation Points WA 7 Observation Point m 18 or Me p Point 1 L e 15 41968 a 11 53991 9 857785 ml 8 195655 Observations v CO BBE Time days JP 4 mot 4 079638 MM plo 0 00 500 125 Bii 1000 475 D 03637904 200 1100 Display as 7300 2500 Elevation OK Cancel 32 Well Name owl X Location 760 Y Location 1667 D Elevation m to edit the location of the observation point type 17 60 iS Time days to enter the observation schedule Time days JP 4 mg L 0 0 500 lt gt 125 lt gt 1000 lt gt 475 gt 2000 lt gt 1100 lt gt 7300 lt gt 2500 iE OK to accept these values Move the mouse anywhere in the model domain and click the left mouse button A New Well dialog box will prompt you for the following information Well Name OW2 lt gt X Location 760 Y Location 1350 lt lt Su type Elevation m 17 60 Visual MODFLOW Tutorial 1S Time days JP 4 mg L 0 0 2000 gt 25 o 7300 200 n OK to accept these p
21. above In addition the next C Zonebudget ET Cancel module contains a compariative solution using an explicit solution using the Method of Characteristics Advection Method Selected for Approximate Time to Complete Transport Simulation using a 300 MHz PII with 128 Mb of RA Implicit Solution using the Upstream 30 minutes Finite Difference and GCG Solver Explicit Solution using the Method of 16 hours Characteristics To continue with this tutorial without running the model press Cancel and select the F10 Main Menu button from the bottom toolbar Module IV Output Visualization If you have run the model you will be visualizing results from your model If you have not run the model you will be visualizing results from the Airport model simulation that is included with the Visual MODFLOW installation CDR If you have just completed MODULE I II amp III and have run the model then you may skip the instruction inside this box From the Main Menu rx File from the top menu t Open t t op the Tutorial folder S Airportd vm ts OK 1S Output 38 Visual MODFLOW Tutorial You will be transferred to the Visual MODFLOW Output options screen By default the output screen will display a plot of equipotential contours without color shading as shown in the following figure Visual MODFLOW C wmodnt T utorial Airport vmf File Contours Yelocit
22. alog box will appear which will default to the last K property that was entered Property 2 Click on the down arrow under the New button so that Property 1 is the active K property DO NOT SELECT OK AT THIS TIME Move the mouse into the discountinuous aquitard area defined by the 0 5 meter contour Press the mouse button down and drag it around the area until the cells within the zone area are shaded white as shown in the following figure Visual MODFLOW D Wmodnt Tutorial Airport vmf Els Grid Wels Eropeties Bounderes Pericles EZB DIG P Ticas a Help Property E Kx m s Ky m s Kz m s u i Hen Row l Column fui Layer K Conductivity edit module Section 4 Assigning Model Properties 17 18 If you have re assigned cells that are outside of the zone release the left mouse button and press the RIGHT MOUSE BUTTON on the appropriate cells to return them to their original property color Once you are finished painting the cells select the OK button in the Assign K Property dialog box Now you will copy this property to layer 4 S Copy from the left toolbar Layer A Copy dialog box will appear with the default settings at Copy only property 1 Layer 4 to highlight it cS OK to copy K Property 1 from layer 3 to layer 4 To check that the K property has been copied to layer 4 select the Next button from the left hand menu to advance t
23. arameters Move the mouse anywhere in the model domain and click the left mouse button A New Well dialog box will prompt you for the following information Well Name OW3 gt X Location 760 Y Location 900 va Elevation m type 17 60 D Time days JP 4 mg L 0 0 vam OK to accept these values iS F6 Zoom Out to refresh the screen To prepare for the next MODULE select F10 Main Menu from the bottom toolbar and select Yes to save your data Module III Running Visual MODFLOW The following guides you through the selection of some of the MODFLOW MODPATH and MT3D run options that are available with Visual MODFLOW To continue with the run options D Run from the Main Menu options You will then be transferred to the run options screen and a dialog box will prompt you to select either a Steady State Flow or Transient Flow simulation ux Steady State Flow Section 9 Designating the Contaminant Source 33 ur OK Section 10 Run Options For Flow Simulations The main run optionsin Visual MODFLOW are divided into four separate sections run options for flow simulations MODFLOW run options for particle tracking MODPATH run options for transport simulations MT3Dxx or RT3D and run options for parameter estimation PEST First you will examine the flow simulation options us MODFLOW va Solver The default solver is the WHS Solver a proprietary solver developedby Waterloo Hydrog
24. e the color scheme by default red is outward i e up when viewing by layer blue is inward i e down when viewing by layer and green is parallel to the plane i e horizontal when viewing by layer Section 13 Velocity Vectors and Contouring Options 43 Visual MODFLOW C wmodnt T utorial Airport vmf File Contours Velocities Pathlines Budget Annotate Tools Help mn View Column LViewLayer View Layer 1 1500 1800 2000 mo ff pos Eze Ear Eg 2 z Vert E30 Heip A Pan Psy Set vertical exaggeration when viewing cross sections Return to the plan view display of the model by selecting the View Layer button from the left hand menu and then clicking on layer 1 in the model cross section To remove the velocity vectors from the screen display select the F9 Overlay button from the bottom menu bar An Overlay Control dialog box will appear with an alphabetical listing all of the available overlays that you may turn on or off Scan down the listing towards the bottom and locate the Results Velocity Vectors Click on Results Velocity Vectors to highlight it and then click on the button labelled ON to toggle it to OFF This should remove the asterisk beside the Results Velocity Vectors indicating that it has been deactivated LS OK to display the screen without the velocity vectors Section 14 Pathlines and Pathline Options 44 Recall that in the input section we assign
25. e values When you are entering the K values Ky will be filled in automatically since Visual MODFLOW assumes horizontal isotropy However anisotropic property values can also be assigned You will now assign conductivity values to the aquitard contained in layers 3 and 4 iS Goto from the left toolbar The Go To Layer dialog box appears type 3 d OK You are now viewing the third layer of model layer 1 is the top layer In this six layer model layers 3 and 4 represent the aquitard separating the upper and lower aquifers The next step in this tutorial is to assign a lower hydraulic conductivity value to layers 3 and 4 The Assign Window function allows you to assign a different hydraulic conductivity inside of a rectangular window Now assign a lower hydraulic conductivity to the aquitard layers 3 and 4 1S Assign 1S Window Move the mouse to the north west corner of the grid and click on the centre of the cell Then move the mouse to the south east corner and click on the centre of the cell This creates a window covering the entire layer An Assign K Property dialog box will appear ZS New the whole grid will turn blue Enter the following aquitard conductivity values Click on the Kx m s text box and enter the following values Kx m s le 10 Ky m s 1e 10 gt Kz m s 1e 11 Section 4 Assigning Model Properties 15 LS OK to accept these values Now copy the hydraulic conductivity propert
26. e will be highlighted and an Assign Constant Head dialog box will appear Enter the following values Section 5 Assigning Model Boundary Conditions 21 Code 2o Stop time day 7300 lt Constant Head Start Pt m 18 Constant Head End Pt m 18 ws OK to accept these values m Copy from the left toolbar is Layer The Copy dialog box will appear Select the Copy only code option and enter a value of 2 in the text box provided p Layer 6 to highlight it um OK to copy the Code 2 constant head values from layer 5 to layer 6 Next assign the constant head boundary condition to the lower confined aquifer along the southern boundary of the model domain ux Assign from the left toolbar m Line Move the mouse to the south west corner of the grid and click on the centre of the cell Then with the RIGHT MOUSE BUTTON click on the centre of the cell in the south east corner of the grid The line will be highlighted and an Assign Constant Head dialog box will appear Enter the following values Code 3o Stop time day 7300 lt gt Constant Head Start Pt m 16 5 lt lt Constant Head End Pt m 16 5 ws OK to accept these values iS Copy from the left toolbar is Layer The Copy dialog box will appear Select Copy only code and enter a value of 3 in the adjacent text box p Layer 6 to highlight it rs OK to copy Code 3 constant head values from layer 5 to layer 6 rz View Column f
27. ed five forward tracking particles to the refueling area To view the fate of these particles us Pathlines from the top menu bar The default screen display will plot all of the pathlines as projections from the current layer of the model as shown below Visual MODFLOW Tutorial Visual MODFLOW C wmodnt T utorial Airport vmf File Contours Velocities Pathlines Budget Annotate Tools Help J 2000 Column J Layer K il Pathline module To show the pathlines in the current layer select the Segments button from the left hand menu This will show only the pathlines that are in the active layer of the model Use the Next button to advance through each layer of the model to see where the particle pathlines are located iS Projections to see all pathlines again Note that the pathlines have direction arrows on them indicating the flow direction These arrows also serve as time markers to determine the length of time before a particle reaches a certain destination To determine the time interval for each time marker select the Options button from the left toolbar and a Pathline Option dialog box will appear as shown below Section 14 Pathlines and Pathline Options 45 E Pathline option x r Pathline Type Color C Steady state Inward BH Maroon Time related Outward A Navy to 10000 day In Plane IBI Green nd Color scheme Time markers g iDrechion haat Regular
28. eologic Inc It is the fastest and most stable MODFLOW solver available For this example the WHS Solver will be used to calculate the flow solution Solver selection OK Cancel Help is OK to accept the WHS Solver A WHS Solver Parameters dialog box will appear showing the default solver settings cS OK to accept the default solver settings During flow simulations it is common for cells to run dry and thus become inactive T eliminate this problem from our solution we will allow MODFLOW to rewet the cells Le MODFLOW S Rewetting iS M Activate cell wetting The Rewetting Options dialog box should now appear as in the figure below 34 Visual MODFLOW Tutorial Rewetting Options Cell wetting interval is Cell wetting factor is Cell Wetting Only wet cells from cells below Wet cells from sides and below Wet dry threshold m Rewet Option Rewet using Re wetting Factor Rewet using Re wetting Threshold uu OK to accept the remainder of the rewetting settings There are still several other run options for flow simulations If you have time investigate the options that were not mentioned in this tutorial Section 11 Run Options for MT3DMS Simulations The next Section will guide you through the selection of the Advection method and solver parameters that you will use to obtain the solution for transport model in this tutorial You will be using the Upstream Finite D
29. fined aquifer an intervening middle aquitard and a lower confined aquifer as illustrated in the following figure The upper aquifer and lower aquifers have a hydraulic conductivity of 2e m sec and the aquitard has a hydraulic conductivity of 1e m sec Recharge 10 cm year 18m 15m 7 12m di Aquifer Ed 10m 2 77 7 6m Aquitard e v v gae gi di 5m 0m Aquifer Lm 0m 4 i p T 2000 m How to Use this Tutorial This tutorial is divided into four modules and each module contains a number of sections The tutorial is designed so that the user can begin at any of the modules in order to examine specific aspects of the Visual MODFLOW environment Each section is written in an easy to use step wise format The modules are arranged as follows Module 1 Creating and Defining a Flow Model Sections 1 through 5 Module 2 Assigning Particles and Transport Parameters Sections 6 through 9 Module 3 Running Visual MODFLOW Sections 10 and 11 Module 4 Output Visualization Sections 12 through 16 Terms and Notations For the purposes of this tutorial the following terms and notations will be used type type in the given word or value select click the left mouse button where indicated e press the lt Tab gt key a press the lt Enter gt key is click the left mouse button where indicated rss double click the left mouse button where indicated 2 Visual MODF
30. he extents of the model area Visual MODFLOW will read the minimum and maximum co ordinates fro the site map Sitemap dxf and suggest a default that is centred in the model domain Visual MODFLOW now allows the user to rotate and align the model grid over the site map use local co ordinates and set the extents of the DXF map If a bitmap was used as background map the image can be geo referenced and the grid can be aligned on the bitmap as well Type the following values over the numbers shown on the screen E Select Model Region O xi File Options Help qij gt elele r1 Display Area xi 0 8911 m Y1l 24 0597 m x2 1998 992 m Y2 1989 354 m Model Origin x 0 m Af D m Angle 0 G Model comers x2 2000 m v2 12000 m NRows 40 NColumns 40 1000 Show Grid X m Model Origin X 0 Y 0 Angle 0 Model Corners X1 0 Y1 0 lt X2 2000 lt gt Y2 2000 lt gt us V OK to accept the mesh dimensions A uniformly spaced 40 x 40 x 3 finite difference grid will automatically be generated within the model domain and a site base map will appear on the screen as shown in the following figure Section 1 Generating a New Model 5 Visual MODFLOW C XvmodntsTutorialXAirport vmf File Grid Wells Properties Boundaries Particles ZBud Tools Help Previous Edit Elevation EditEstents mport Elevation Column J Layer K 1
31. ialog box you will enter the model domain dimensions and specify the units for your model p C vmodnt T utorial Airport vmf IV Create model using base Map Units Map File C Avmodnt T utorial Sitemap dxf Browse Length meters gt Model Domain ane s rl Columns i 40 Rows i jo oat r Conductivity m second Amm fo m Ymin fo m Allee fi 000 m Vinee fi 000 m Pumping Rate n day Layers k Recharge mm vear Zmin o m B Zmax fis m Mass ko I Setup Transport Model Concentration mg L Cancel M Create model using base Map Next you must specify the location and the file name of the DXF background map 1S Browse Navigate to the tutorial directory default c VMODNT Tutorial and select the following file cS Sitemap dxf 6r Open Next you will specify the number of rows columns and layers to be used in the model Enter the following into the Model Domain section Number of Columns j 40 Number of Rows i 40 lt gt Number of Layers k 3o Zmin 0 Zmax 18 lt Under the Units section specify the following information using the mouse pointer and the individual drop down lists Length meters Time days Conductivity m second Pumping Rate m day Recharge mm year Mass kg Concentration mg L Visual MODFLOW Tutorial cS Create to accept these settings A Select Model Region dialog box will appear prompting you to define t
32. ies Pathlines Budget Annotate Tools Help LEKE ORR x 28 3 Y 1405 1 2 17 9 Row l 22 1200 1500 Column J Layer K Output Time 1 00000 day Stress period 1 Time step 1 To see a list of contouring capabilities select Contours from the top menu bar A drop down menu will list the following contour selections Contours Head Equipotentials Head Difference Head Flux Drawdown Elevation Net Recharge Water Table Concentration Select Head Equipotentials to return the plot of equipotentials Section 12 Equipotentials and Contouring Options To select contouring options for Equipotential Heads iS Options from the left toolbar Section 12 Equipotentials and Contouring Options 39 40 The Results Head Equipotentials dialog box will appear as shown below By Results Head Equipotentials In the box labelled Interval change the value from 0 5 to 0 25 In the box labelled Contour Labels change the number of Decimals to 2 You can change the contouring speed and resolution by clicking on the combo box labelled Contouring resolution Speed For this exercise the default setting of Highest Slowest is fine To activate color shading D Colour Shading tab S Mi Use Color Shading a Results Head Equipotentials fs rams pr eas femm zl LN Visual MODFLOW Tutorial m OK to accept these contouring options The location of the contours should
33. ies of layer 3 to layer 4 us Copy from the left toolbar vam Layer A Copy dialog box will appear mx Mi Copy all properties S Layer 4 this will highlight it ms OK to copy the K Properties in layer 3 to layer 4 Although the model layers show the aquitard pinch out to be a very small thickness 0 2 m in the discontinuous aquitard zone it is good practice to re assign the K values in this zone to properly represent the discontinuity of the aquitard In this particular example the zone of discontinuous aquitard is delineated on the base map However in many cases this will not be available and you will need to rely on parameters such as layer thickness for determining discontinuous zones To display the thickness of layer 3 select the F9 Overlay command button from the bottom toolbar An Overlay Control dialog box will appear as shown below containing an alphabetized listing of the available overlays which may be displayed while assigning model input parameters Overlay Control Overlay Name C Layer Bottom Elevation 4 Overlay is C Layer Thickness C Layer Top Elevation CBC Constant Concentration Boundaries CBC Evapotranspiration Concentration CBC Initial Concentration CBC Point Source Concentration Boundaries Settings CBC Recharge Concentration HBC Constant Head Boundaries HBC Drain Boundaries Delete HBC Evapotranspiration HBC General Head Boundaries aveta Order Pumping We
34. ifference advection method and you will be applying the Generalized Conjugate Gradient solver to find an implicit rather than explicit solution D MT3DMS from the top menu bar a Advection from the drop down menu An Advection Method dialog box will appear as shown in the following figure Advection Method x m dvection Method Method of Characteristics MOC Raricle Gptions Solver Parameters C Modified MOC MMOC C Hybrid MOC MMOC HMOC Courant number 7 5E 1 Minimum saturated thickness 1E 2 Central Finite Difference as a fraction of cell thickness C TVD OK Cancel Section 11 Run Options for MT3DMS Simulations 35 36 Lg Upstream Finite Difference The Upstream Finite Difference advection method provides a stable solution to the contaminant transport model in a relatively short period of time Lg Solver Parameters iS M Use Generalized Conjugate Gradient Solver iS Vl Translate GCG Solver Package Though the Upstream Finite Difference method and the GCG Solver are computationally efficient the tutorial simulation tracks contaminant transport over a 20 year period In order to speed up the modelling process you will use a non linear time step In the Time Steps box select Multiplier type 1 01 Since the time steps will increase exponentially you will cap the maximum time step as being 200 days Select Maximum transport step size type 200 The GCG Solver Settings dial
35. in cross section Select the View Column button from the left toolbar and then move the mouse into the model domain Choose a column near the middle of the model domain by clicking the left mouse button To remove the custom contours click the RIGHT MOUSE BUTTON in the cross section and the contouring options shortcut menu will appear Section 12 Equipotentials and Contouring Options 41 S Delete all custom i View Layer to return to the plan view of the airport site Before proceeding to the next section the color shading should be turned off va Options from the left toolbar vam Reset i Color Shading tab us O Use Color Shading to remove the v er OK Section 13 Velocity Vectors and Contouring Options Velocity vectors are an excellent way to visualize the speed and direction of a water particle as it moves through the flow field To use this tool LS Velocities to view the velocity vectors You will automatically be transferred to the Velocity Vectors output options screen as shown in the following figure The velocity vectors will be plotted according to the default settings that plot the vectors in relative sizes according to the magnitude of the flo velocity Visual MODFLOW C XvmodntsTutorialXAirport vmf File Contours Yelocities Pathlines Budget Annotate Tools Help g eerte t tt n amp 3 W X cS soe ht tee ee 5 56 5s HN he Ae Pe e a a eG E e E ee a a ee d Ww o 9 E
36. izontal line is within the layer representing the aquitard and press the RIGHT MOUSE BUTTON An Add Horizontal Layer dialog box will appear as follows Add Horizontal Layer Add horizontal layer at m with minimum thickness of m Split current layer into e evenly spaced layers Add layer at from bottom of current layer OK Cancel Help Section 2 Refining the Model Grid 11 is Split current layer into 2 evenly spaced layers OK Repeat this action for the bottom layer of the model When you have completed these instructions Ss Close to exit the Layers dialog box The model cross section should now consist of six layers and should appear similar to the following figure when viewing column 30 Visual MODFLOW D Wmodnt Tutorial Airport _vmf File Grid Wells Properties Boundaries Particles ZBud Tools Help Edit Elevation LEditExtents Import Elevation 1200 1500 1800 2000 Jang i uot Grid edit module Use the Next and Previous buttons on the left toolbar to advance through the column cross sections of the model Next select the View Row toolbar button Select a row from the cross section by moving the cursor into the model domain and clicking on one of the highlighted vertical columns Try advancing through the row cross sections of the model To return to the plan view of the model domain
37. l appear as shown in the following figure Section 8 Assigning Chemical Reaction Parameters 29 JP 4 Parameters Database 1 58E 7 1 58E 7 1 58E 7 1 58E 7 1 58E 7 Ok Cancel The default distribution coefficient was specified during the setup of the numeric engines We see that each of the layers of the model contains this default value New values can be specified for each layer or zones within a layer can be specified as having an alternate distribution coefficient ud Ok Section 9 Designating the Contaminant Source 30 We are now ready to designate the contaminant source The source of contamination will be designated at the refuelling area as a recharge concentration that serves as a source of contamination to infiltrating precipitation us Boundaries from the top menu bar is Recharge Concentration Check to ensure that you are viewing layer 1 by referring to the navigator cube in the lower left hand side of the screen If you are not displaying layer 1 use the Previous Next or Goto buttons on the left toolbar to advance to the first layer LS F5 Zoom In and stretch a zoom window over the refuelling area Assign the concentration to the natural recharge entering the model at the refuelling area vam Assign from the left toolbar i Polygon Move the mouse around the perimeter of the refuelling area clicking on the corners of the area with the left mouse button then click the RIGHT M
38. lete the entire exercise Description of the Example Model The site is located near an airport just outside of Waterloo The surficial geology at the site consists of an upper sand and gravel aquifer a lower sand and gravel aquifer and a clay and silt aquitard separating the upper and lower aquifers The relevant site features consist of a plane refuelling area a municipal water supply well field and a discontinuous aquitard zone These features are illustrated in the following figure REFUELLCWB RRER ACRPORT OWE O CONTLHUDUB PUCTARO 2 g WELLE BUPPLY Fiuen p Sarees ALUER The municipal well field consists of two wells The east well pumps at a constant rate of 550 m day while the west well pumps at a constant rate of 400 m day Over the past ten years airplane fuel has periodically been spilled in the refuelling area and natural infiltration has produced a plume of contamination in the upper aquifer This tutorial will guide you through the steps necessary to build a groundwater flow and contaminant transport model for this site This model will demonstrate the potential impact of the fuel contamination on the municipal water supply wells When discussing the site in plan view the top of the site will be designated as north the bottom of the site as south the left as west and the right as east Groundwater flow is from north to south top to bottom in a three layer system consisting of an upper uncon
39. lls wol par Recharge Default River Boundaries Wall HFB Boundaries Annotation Grid Moye te Tap Inactive Cells Inactive for Transport Cells Observation Wells for Concentration One Up Observation Wells for Heads Particles Zone Budget Zones User defined Bulk Density Chemical Reaction Zones Conductivity Dispersivity Initial Head OK Cancel Mose toBbotan Gre Down Scan list until for C Layer Thickness Double click on C Layer Thickness and an asterisk will appear to the left indicating that it is now an active overlay Visual MODFLOW Tutorial is OK to display a contour plot of the layer thickness Now zoom in on the area where the contours converge towards a minimum thickness of 0 5 meters Note If you are having difficulty viewing the contours because of the background color follow these steps Click F9 Overlay Single click on the C Layer Thickness overlay From the side menu in the Overlay Control dialog box select Settings You will be able to alter the contour colours from the drop down list provided us F5 Zoom In Move the mouse to the upper left of the discontinuous aquitard zone and click the left mouse button Then stretch a box over the area and click again A zoomed image of the discontinuous aquitard zone should appear on the screen is Assign iS Single to assign a property to an individual cell An Assign K Property di
40. n that of MOC Although both simulations are numerically stable professional judgement should be used to determine the allowable amount of numerical dispersion There were three output times specified for these MT3D simulations 1825 days 3650 days and 7300 days Select the Time button on the left toolbar to see a list of the output times is 7300 to highlight it OK to plot the concentration contours after 7300 days The following figures show the 7300 day contaminant plume for Upstream Finite Difference and MOC respectively Visual MODFLOW Tutorial Visual MODFLOW C wmodnt T utorial Airport vmf File Contours Yelocities Pathlines Budget Annotate Tools Help BUPPLY bd n WELLE X 1609 1 Y 1643 1 Zee Row I 200 1500 2 E 1 10 Column J FB vonl EZ F8 vert E3 nue Layer K iG exa Atay RT3D Overlay Results JP 4 Time 7300 00000 day Stress period 1 Time step 1 Visual MODFLOW C XvmodntsTutorialXAirport vmf File Contours Velocities Pathlines Budget Annotate Tools Help S View Layer Select BUPPLY o o FELLE x 1575 1 Y 250 Z 16 3 i l 1 Row I B5 d 300 600 300 1200 1500 2000 Column J F S 5 Layer K S i Section 15 Concentration Contours 5 After 7300 days of simulation it is clear that the amount of numerical dispersion with the Upstream Finite Difference is pronounced as compared to the Method of Characteristics Secti
41. ning Particles and Transport Parameters If you have just completed MODULE I then you may skip the instructions inside this box i File t Open A File Selection dialog box will appear r on the Tutorial folder r Airport2 vm The file will be opened and you will be presented with the Visual MODFLOW Main Menu t Input Section 5 Assigning Model Boundary Conditions 25 Section 6 Assigning Particles In this section you will be guided through the steps necessary to assign forward tracking particles to determine the preferred contaminant exposure pathways 1s Particles from the top menu bar You will be asked to save your data ws Yes The first step is to zoom in on the refuelling area wz F5 Zoom In from the bottom toolbar Click the left mouse button near the top left corner of the refuelling area then drag a window over the area and click on the left mouse button again to close the zoom window Add um Add Line Move the cursor to the left side of the refuelling area and click the left mouse button Stretch a line to the right side of the refuelling area then click again A Line Particle dialog box will appear The default number of particles assigned is 10 Change the number of particles to 5 rs OK to assign the line of 5 particles in the refuelling area The line of green particles through the refuelling area indicates forward tracking particles Now return to the full screen display of
42. nsport Variant have been changed If the primary settings have been changed you must either create a new transport Variant or re initialize the current transport Variant In either case the transport Variant will contain only the default settings for the transport parameters All boundary conditions initial conditions etc must be re entered or copied from another variant The primary settings of a transport Variant always includes the number of species and the transport engine MT3D1 5 RT3D etc Depending on the model it may also include the sorption isotherm the chemical reaction model and other parameters Note The default values for parameters such as initial concentration are used only during model creation These values must be updated in the Input module Variant Renitialize the transport Variant and save the new settings C Create a new transport Variant Variant Name fvar001 Description OK Cancel You now have the option of re initializing and saving the new variant settings or saving your changes as a new variant We will replace the previous Var001 variant with our new settings Ok You will now be returned to the Main Menu of Visual MODFLOW 1S Input Section 8 Assigning Chemical Reaction Parameters S Properties from the top menu bar m Species Parameters 1S Database from the left toolbar The JP 4 Parameters Database dialog box wil
43. o layer 4 m F6 Zoom Out to return to the full screen display of the entire model domain To see the model in cross section select View Column from the left toolbar and move towards the discontinuous aquitard zone Select the desired column location by clicking the left mouse button A cross section will be displayed as shown in the following figure Use the Next and Previous buttons on the left toolbar to advance through the model Refer to the cube navigator on the lower left of the screen to see the relative cross section location Visual MODFLOW D Wmodnt Tutorial Airport1 vmf File Grid Wells Properties Boundaries Particles ZBud Tools Help N col i E eee PER eee or o l m i I I 1 U 1 1 0 300 600 300 1200 1500 1800 x 987 5 Y 483 9 Z 252 Row l Column J 30 Layer K Conductivity edit module Visual MODFLOW Tutorial Return to the plan view display by selecting the View Layer button and then clicking on layer 1 in the model cross section To remove the layer thickness contours select F9 Overlay from the bottom menu bar Scan the list of overlays and double click on the C Layer Thickness to deactivate it from the overlay display Er OK The default initial heads condition for a new model can be viewed by pressing Properties iS Initial Heads pz Database from the left toolbar Visual
44. of simulation only option by clicking inside the box to remove the v then fill in and check off the following Simulation Time 7300 days Click in the box labelled Max of transport steps type 10000 ps specified times In the boxes below the 9 Specified times label enter the following values 1825 J 3650 um 7300 iS OK to accept these Output and Time Step Control parameters This concludes the MT3D run options section of the tutorial Again there are many other run options that have not been covered in this tutorial If you have time investigate some of the other options available Although you could run the model at this time you may not want to because of the length of the simultation If you would like to run the model follow these steps Select Run from the top menu bar A Translate Run dialog box will appear Section 11 Run Options for MT3DMS Simulations 37 Select the numerical engines you wish to run When you click on the Translate amp Run button Visual MODFLOW will create the standard input files for the MODFLOW MODPATH and MT3D programs Visual MODFLOW will then start the Win32 MODFLO Suite which controls the numeric engines For more information see the Visual MODFLOW User s Manual When the simulation is complete you will be returned to the Visual MODFLOW Main Menu ae The following table outlines the approximate time that it will take to lode run the model given the input described
45. og box should appear as follows GCG Solver Settings x V Translate GCG Solver Package Maximum number of outer iterations fi Maximum number of inner iterations 50 Preconditioners Jacobi C ssoR Relaxation factor fi C Modified Incomplete Cholesky M Dispersion tensor cross terms Lump all dispersion cross terms to the right hand side Include full dispersion tensor memory intensive Relative convergence criterion 0 0001 Concentration change printing interval o Time Steps Initial step size o day Multiplier 1 01 Maximum transport step size 200 day Ok Cancel Help cS OK to accept the GCG Sover Settings m OK to accept the Advection Method settings Visual MODFLOW Tutorial MT3DMS is Output Time Steps An Output amp Time Step Control dialog box will appear as shown below b Output amp Time Step Control Simulation time tes day s Max transport Steps fi 000 T Specify max stepsize fo day s Save simulation result at the end of simulation only Save simulation results at specified transport steps specified times day s Save each fi step s 3650 7300 Save CBM file x Cancel The default setting for MT3D output control is to save only one set of concentration data values at the end of the simulation First deactivate the M Save simulation results at the end
46. on 16 Concentration vs Time Graphs In this section you will learn how to display your observed data against the model s predictions From the right menu bar 1S Conc vs Time You will then be presented with the graph for Concentration vs Time In order to view the breakthrough curves at each of your concentration observation wells Select A All from the Groups box on the left hand side of the window 5 Apply You should now be viewing the breakthrough curves for each of the three concentration observation wells defined earlier in the model see following figure E Concentration vs Time C ymodnt Tutorial Aiport File Edi View Info Options Help B 53 BAMA A AACR BAMA AA Group Concentration vs Time 7 All groups E OOW1 Obs P 4 OW Point 1P 4_ OWAXObs UP A e OW2Point 1 0P 4 Alluser groups A OWXObs UP 4 de OWS Point 1 4UP 4 P All layer groups 1 v All well groups Species V JP 4 Concentration mg L 1000 v Selected points 0 2000 4000 Time dy 6000 Time dyJ n a Concentration mg L n a For comparison a copy of the same breakthrough curves for the Method of Characteristics solution is shown below Notice the jagged nature of the MOC plot This is due to the discrete nature of the MOC solution 52 Visual MODFLOW Tutorial E Concentration vs Time C vmodnt Tutorial Airport All L1 Layer 1 wW1 0w1
47. orner of the grid A horizontal line of cells will be highlighted and an Assign Constant Head dialog box will appear as shown in the following figure Visual MODFLOW Tutorial Assign Constant Head I Assign to appropriate layer Import Start Stop Constant Time day Time day Head m Erde OK Cancel Help Enter the following values Code loo Stop time day 7300 Constant Head Start Pt m 19 lt Constant Head End Pt m 19 ms OK to accept these values The pink line will now turn to a dark red line indicating that a constant head boundary value has been assigned Lg Copy from the left hand menu 1S Layer The Copy dialog box will appear with the default setting Copy only code and a value of T in the adjacent text box iS Layer 2 to highlight it iS OK to copy Constant Head Code 1 from layer 1 to layer 2 We will now enter the constant head boundary for the lower confined aquifer along the northern boundary of the model domain S Goto on the left toolbar The Go To Layer dialog box will appear In the Layer you wish to go to text box the number 1 will be highlighted as the default setting type 5 S OK to advance to layer 5 i Assign from the left toolbar i Line Move the mouse to the north west corner of the grid and click on the centre of the cell Then with the RIGHT MOUSE BUTTON click on the centre of the cell in the north east corner of the grid The lin
48. ouse button on the desired column Visual MODFLOW transfers the screen display from plan view to a cross sectional view of the model grid At this point the model has no vertical exaggeration and the cross section will appear as a thick line with the three layers barely discernible To properly display the three layers you will need to add vertical exaggeration to the cross section va F8 Vert Exag from the bottom of the screen A Vertical Exaggeration dialog box appears prompting you for a vertical exaggeration value type 40 Visual MODFLOW Tutorial ir OK The three layers of the model will then be displayed on the screen as shown below From the figure you can see that each layer has a uniform thickness across the entire cross section Visual MODFLOW C wmodnt T utorial Airport vmf File Grid Wells Properties Boundaries Particles ZBud Tools Help Edit Grid gt Edit Elevation Import Elevation oO oe oL or w im 1 1 1 1 1 1 0 300 600 900 1200 1500 1800 2000 i Fl F2 r3 rm r5 FB Fe OFS d ES Zi 2 t Pw Bod ao s e 224 ran ite P Grid edit module Visual MODFLOW allows you to import variable layer elevations from surfer grd files or from space delimited x y z ASCII files In this example we will import an ASCII x y z file to create a sloping ground surface topography and layers with variable thickness us Import Elevation from the left hand menu
49. r our default species is Conc001 This shortname can be edited to reflect your species of interest Conc001 type JP 4 The Component Description can also be edited rs Component 001 type Spilled Jet Fuel The default setting for species mobility is Yes and the default initial concentration for the entire domain is zero To add a new species select the New Species button located beneath the spreadsheet 1s New Species Section 7 Assigning Model Transport Parameters 27 28 us Conc002 type TCE For our model we will use a single species the spilled jet fuel S Delete Species S Yes to delete TCE The species information is now set up properly and should appear similar to the figure below 3 Transport Engine Options MT3DMS 7 Lear sta esi conte z Spilled Jet Fuel i Model Params tab Resize the columns of the spreadsheet so that you can read the text contained in the cells For this simple model we will use the default bulk density value of 1700 kg m us Species Params tab You will notice that the Designation of the contaminant has been changed in the last column Also the variable SP1 distribution coefficient now contains the default value set in the Species tab Visual MODFLOW Tutorial We are now ready to exit the Transport Engine Options dialog box od Ok The Replace Variant dialog box will appear AN Replace Yariant ICE x The settings for this tra
50. rom the left toolbar Move the mouse into the model domain and select the column passing through the zone of discontinuous aquitard A cross section similar to that shown in the following figure should be displayed Visual MODFLOW Tutorial Visual MODFLOW D Wmodnt Tutorial Airport1 vmf File Grid Wells Properties Boundaries Particles ZBud Tools Help Next N m 300 600 ado 12 200 1500 18 500 2000 x 987 5 Y 588 7 Z 27 4 Row l Column J 30 F1 F2 E3 F4 F5 5 F8 5 F F8 verti E3 Quer Layer K lal save nap in out t Pan erao P La Constant head edit module The hydraulic conductivity property colors can also be displayed at the same time Select F9 Overlay and the Overlay Control dialog box will appear providing a list of available overlays that may be turned on and off Using the mouse double click on Prop Conductivity An asterisk will then appear beside the overlay indicating it is active m OK to display the hydraulic conductivity overlay Now return to the plan view display of the model domain by selecting the View Layer button from the left toolbar and clicking on the top layer Next you will assign a river boundary condition in the top layer along the southern boundary of the model domain D Boundaries us Rivers to transfer to the rivers input screen am Assign from the left toolbar
51. u can have more than one variant for a given flow model By default Visual MODFLOW creates a variant named VAR001 We will now edit this variant to setup the model for transport processes 1s Edit in the Select Transport Variant dialog box You will then be presented with the Transport Engine Options dialog box A warning message will appear It informs the user that changes to the variant will result in the user being required to edit the transport variables in the input module Zs Close From the Sorption or dual domain transfer drop down list you will see that there are a number of options available for defining the method of sorption used by the model For our model we will select a linear isotherm pu Linear Isotherm equilibrium controlled From the Reactions drop down list you will see that there are two reactions available For our simple model we will select No Kinetic Reaction ne No kinetic reactions Below the sorption and reaction drop down boxes are four tabs labelled Species General Model Params and Species Params 1S on the Species tab In the Species tab you will see a spreadsheet view with labelled column headings The last two columns are labelled with MODFLOW variable names For a better description of each of the variables hold the mouse cursor over the column labels to display a text bubble rz SP1 Distribution Coefficient 1 mg L type 1 58e 7 You will notice that the Designation fo
52. un 2500 mg L Min 7 ro a Cut off Levels B os EE Upper mi B 20555 MEN Lower 0 5 Iv E 7 MEM Chie EM r s AN Max 7 B Reset OK Cancel d OK The following figure shows the concentration contours at 1825 days using the Upstream Finite Difference method and the Generalized Conjugate Gradient Solver Visual MODFLOW Tutorial Visual MODFLOW C wmodnt T utorial Airport vmf File Contours Yelocities Pathlines Budget Annotate Tools Help SUPPLY bd n WELLE X 1503 4 Y 362 6 Z 164 Row I 63 0 E 300 900 1200 1500 20 I 00 Column J 55 Ea Foz EE zool FA ES vert ES ove Layer Ki 1 aut A Pan Kl eso Atay RT3D Overlay Results JP 4 Time 1825 00000 day Stress period 1 Time step 1 The next figure shows the contaminant plume generated using the Method of Characteristics MOC for comparison Section 15 Concentration Contours 49 50 Visual MODFLOW C vwmodnt T utorial Airport vmf File Contours Yelocities Pathlines Budget Annotate Tools Help Select gt ap me BUPPLY o o FELLE x 0 0 Y 549 6 Z2 i Row ly 57 s00 1200 1500 2000 Column J Layer K RT3D Overlay Results JP 4 Time 1825 00000 day Stress period 1 Time step 1 The contaminant transport simulation using the Upstream Finite Difference method shows higher values of numerical dispersion tha
53. undary Conditions Module II Assigning Particles and Transport Parameters Section 6 Assigning Particles Section 7 Assigning Model Transport Parameters Section 8 Assigning Chemical Reaction Parameters Section 9 Designating the Contaminant Source Module III Running Visual MODFLOW Section 10 Run Options For Flow Simulations Section 11 Run Options for MT3DMS Simulations Module IV Output Visualization Section 12 Equipotentials and Contouring Options Section 13 Velocity Vectors and Contouring Options Section 14 Pathlines and Pathline Options Section 15 Concentration Contours Section 16 Concentration vs Time Graphs 1999 Waterloo Hydrogeologic Inc DW QJ UNNE 13 14 19 25 26 26 29 30 33 34 25 38 39 42 44 46 52 Visual MODFLOW Tutorial This chapter presents a tutorial with a complete set of input and output files for an example model Airport that will allow you to examine the post processing features and capabilities of Visual MODFLOW The numerical simulations MODFLOW MODPATH and MT3D for this problem have already been completed to allow you to evaluate the output visualization features for the sample model results This tutorial guides you through some of the steps necessary to design and run a model and visualize the results The instructions for the tutorial are provided in a step wise format that allows you to choose the features that you are interested in examining without having to comp
54. wa2 0w2 w3 0w3 RI TAS Xl There are a number of other graphing features available in the output section of the Visual MODFLOYW environment Take time to examine the Calibration Plots the Calibration Residual Histograms as well as the Normalized RMS vs Time Graph Each of these graphs display useful information and statistics which you can use to fine tune your model for the most accurate solution This concludes the Visual MODFLOW Tutorial Section 16 Concentration vs Time Graphs 53
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